1. Field of the Invention
The present invention relates to products and methods to provide common surfaces with antimicrobial properties to fight bacteria, viruses and fungi.
2. Invention Disclosure Statement
Surfaces of many consumer goods and industrial items are regularly populated by bacteria, viruses and fungi, which can produce health hazards. Cleaning and disinfecting these common surfaces is an everyday hygienic process. Cleaning and disinfecting do not always yield satisfactory results, since many microbes have increasingly become resistant to many of the agents currently being used. Chemical compositions used to disinfect surfaces often have a broad non-specific action and may be health risks to people with allergies or chemical sensitivities.
U.S. Pat. No. 4,532,269 describes a terpolymer that is used as an antimicrobial paint for ships. The coating slowly erodes to produce a highly toxic compound that keeps the paint antimicrobially active. Coatings of this type will lose their action when the active ingredient in the paint eventually migrates to an ineffective level. The toxic compounds created by this invention make it impractical for use in consumer goods or common industrial items.
U.S. Pat. No. 5,534,346 describes an attachable thin film prophylactic barrier used to prevent the spread of infectious disease during medical procedures. The invention is visually transparent or translucent plastic sheet with a pressure sensitive adhesive back. The described invention is a physical barrier and does not have any antimicrobial properties.
U.S. Pat. No. 5,967,714 describes a process for the preparation of antimicrobial polymer surfaces wherein tert-butylaminoethyl methacrylate is graft copolymerized with an aliphatically unsaturated monomer on a polymer substrate. The substrates surface is activated by methods such as UV radiation before the graft polymerization takes place. The described invention is limited to polymer substrates, and antimicrobial protection is only provided at the time the product is manufactured. The invention does not describe how to provide antimicrobial properties to a previously manufactured item.
U.S. Pat. No. 6,214,901 describes a composition for coating a medical device with bioactive agent in a manner that permits the coating to release the bioactive agent over time when implanted in vivo. The described coating composition is particularly adapted for use with devices that undergo significant flexion or expansion in their use. Covering consumer items with the described bioactive agent coatings is not practical since it can interfere with the appearance and utility of the items to be protected.
U.S. Pat. No. 6,080,490 describes an actively sterile surface for a substrate in a biologically dynamic environment. The described invention consists of an antimicrobial element in combination with an electrochemically nobler element that forms multitudinous galvanic cells with biological fluids to release the antimicrobial elements at the target site. Since most commercial and industrial items do not contact biological fluids, use of the described invention to protect such surfaces is not feasible.
U.S. Pat. No. 5,534,346 describes an attachable thin film prophylactic barrier used to prevent the spread of infectious disease during medical procedures. The invention is visually transparent or translucent plastic sheet with a pressure sensitive adhesive back. The described invention is a physical barrier and does not have any antimicrobial properties.
The inventor has previously described (in co-pending U.S application Ser. No. 09/345282 filed on Jun. 30, 1999) medical catheters and implants whose surfaces are covered by photosensitizers or contain photosensitizers. An embodiment of the invention has a photosensitizing compound affixed to or near the device surface with means to periodically activate the compound by suitable illumination. Bacterial growth and adherence to medical devices is overcome for extended periods of time by using the invention. It is impractical to cover consumer items in a similar manner as bleaching will occur over time due to exposure of the surfaces to ambient light. The use of laser as the activation radiation may also be impractical.
It would be useful to have a method to impart antimicrobial properties to product surfaces after they are manufactured, where the microbial action is renewable, and where the microbial agent does not permit the development of resistance by the microbes.